1. Field of the Invention
The present invention relates to a femoral compression device and a method for hemostasis of the femoral artery following, for example, catheterization. More particularly, the invention relates to a femoral compression device including a pressurizing means which presses on the femoral artery.
To be able to visualize arteries and veins with contrast medium during, for example, heart catheterization and angiography, one often enters via the femoral artery in the groin. Investigations via the femoral artery are especially difficult because of the high pressure against the artery wall. Today an investigation like that is performed by making a small incision in the femoral artery using a small diameter cannula. A guide is inserted into the cannula and into the artery, and thereafter a catheter is threaded over the guide into the artery. Thereafter the guide is removed and contrast medium is injected through the catheter into the artery.
After the investigation is completed, the catheter is withdrawn, leaving a wound, and the bleeding from the incision site in the femoral artery is stopped. This can be done manually, when, for example, the physician presses his finger against a compressive bandage laid on the wound for about 20 minutes. Obviously this is not a satisfactory method since it is inconvenient for both patients and physicians and also requires valuable physician time. Furthermore, it is difficult for the physician to maintain a constant pressure.
2. Discussion of the Related Art
Several devices have also been proposed by which a pressure is applied onto the wound in the femoral artery.
U.S. Pat. No. 4,509,528, issued May 9, 1985, to Sabota, describes a hemostat with a blood flow sensor. The sensor measures the blood flow and can be of, for example, the Doppler type. The signal from the sensor is processed by a signal processor, which in turn produces a second signal, preferably a sound, varying in volume in response to changes in the blood flow through the blood vessel. This arrangement is well known and described earlier. When the sound, and thus also the blood flow, varies, the latter is to be reset manually by a number of adjustments. Thus there exists no feed back from the sensor to the operating means.
U.S. Pat. No. 4,770,175, issued Sep. 13, 1988, to McEwen, describes a device for occluding, but not registering, blood flow into a digit. The device is provided with a pressurizing means and a sensor sensing the pressure exerted by the pressurizing means against the digit. The signal from the sensor is digitally processed and thereafter a signal goes to the pressurizing means in such a way that a constant, occluding pressure always acts on the digit. Thus the device does not include a sensor measuring blood flow. The Doppler device illustrated in the patent is only used to obtain standard curves to establish occluding pressure levels for different cuff and digit dimensions.
In U.S. Pat. No. 3,625,219, issued Dec. 12, 1991, to Abrams, et al., there is shown a device for hemostasis in which an inflatable balloon is used as pressurizing means. However this device involves a complex and unstable construction and does not allow patient movement. Like the above devices, this one does not comprise a feed back from the sensor to the pressurizing means.
The principle of these devices is the same: a pressure is applied on the incision site in the femoral artery for about 20 minutes following completed catheterization. The pressure is to be set high enough to stop bleeding but not so high that the blood flow is cut off down to the leg and foot.
Following balloon dilatation of the femoral artery in the leg it is especially important not to apply too high a pressure on the incision site as there is a risk that the dilated stenosis in the artery will contract if the blood pressure is too low. To avoid blood clots, the patients are given anti-coagulating agents, such as heparin, prior to the treatment. This of course extends the time required to stop the bleeding after having completed the procedure. For patients already taking heparin for medical reasons, the time will be as long as up to 1.5 hours. However, if insufficient pressure is applied, hematoma is a common side effect.